1. Field of the Invention
The present invention generally relates to a printer having a paper roll container in which a paper roll where belt-shaped paper is wound plenty of times is loaded and the loaded paper roll in the paper roll container can be easily exchanged for a new paper roll.
2. Description of the Related Art
In a printer using a paper roll, when the remaining amount of paper in the paper roll becomes approximately 1 to 2 meters (this is called the “near-end state”), the near-end state is detected and reported to a user for exchanging the paper roll for a new paper roll. In many cases, as the paper, thermosensitive paper is used when using a thermal printer.
In many cases, a printer using thermosensitive paper includes a so-called “easy loading mechanism”. In the “easy loading mechanism”, the printer provides a paper roll container for containing a thermosensitive paper roll and a lid for closing an opening section of the paper roll container by being rotated, and when the remaining amount of thermosensitive paper in the thermosensitive paper roll becomes low and a new thermosensitive paper roll is loaded in the thermosensitive paper roll container by exchanging the old one for the new one, the tip of the new thermosensitive paper is pulled out and sandwiched between a thermal head and a platen roller. That is, the thermosensitive paper roll can be easily exchanged by the “easy loading mechanism”.
In order to easily exchange the thermosensitive paper roll, the printer having the easy loading mechanism needs to provide a mechanism to detect the near-end state. Hereinafter the mechanism to detect the near-end state is referred to as a near-end detecting mechanism.
The printer is built in, for example, a POS (point of sale) apparatus. Since the POS apparatus is installed in a shop, the size of the POS apparatus is required to be small and the size of the printer itself is also required to be small.
A conventional printer using the easy loading mechanism includes the near-end detecting mechanism on the side surface of the printer main body (refer to Patent Document 1).
[Patent Document 1] Japanese Laid-Open Patent Application No. 2004-262059
Since the near-end detecting mechanism is stuck out from the printer main body, the printer cannot be small sized and the POS apparatus including the printer also cannot be small sized.